CD 175 Rebuilders

[101RRS]

I have two two Zenith Stromberg CD 175 carbs that I would like to get rebuilt - they are getting a bit worn and probably got a bit of crud in them.

Looking for good but cheap ([thumbsupbig]) carb specialists in the Sydney area who could do the work. Yes I can google carb specialists in Sydney and get a big list but not know who is good or bad so looking for recommendations from happy customers.

Thanks

Garry

[discojools]

Had mine done by B and M Fuel Systems in Airport West here in Melbourne. Blokes name is Tony I think. Did a great job.

[rick130]

Carburettor Service Co at Burwood used to be my go to for shaft rebushing, etc. for my race carbies back in the day.
They were on Parramatta Rd, Burwood.

[PhilipA]

Really they are very simple devices, especially if you don't have the really early ones with the hole with spring in the throttle blade.
I would DIY in your position. a careful dismantle and clean with new gaskets for the choke and new needles and jets will work wonders. AFAIR the throttle spindle has a nylon bush to take up wear, so really shouldn't need rebushing.

I have a suspicion of carby rebuilders since my neighbour had the 175s on his XJ6 coupe rebuilt and it would hardly run afterwards. I had a look and found that on one the throttle blade was maladjusted and was sticking closed and it was running on one carb, as the linkage join was turning instead of the throttle. Several quick open/shuts and a tighten of the linkage "W" join alleviated the problem but pretty poor to me.

Regards Philip A

[101RRS]

Carburettor Service Co at Burwood used to be my go to for shaft rebushing, etc. for my race carbies back in the day.
They were on Parramatta Rd, Burwood.

Thanks - I just googled carby rebuilders sydney and they cam up first - I rang them and seemed very helpful and knowledgeable.

[101RRS]

Really they are very simple devices, I would DIY in your position.

Yes as an initial action I am thinking the same - rebuild prices are $350 per unit and i have two.

The carbs ran fine 2 years ago when the manifold they were on was taken off and stored in the shed - not working now. So maybe old fuel has dried out leaving varnish inside. I will take the carbs off and dismantle but not change any adjustments - clean up with carby cleaner and a bit of low pressure air and see what happens. I have checked the diaphragms and they are still good. Looking a Youtube it seems the float valve can stick with lack of use so I will check that.

If no luck doing a basic clean then will then look at further actions.

Thanks

Garry

[FisherX]

G'day Garry,

I would't go anywhere else than Sumidel in Lakemba in Sydney. They are SU specialists and really know what they are doing. I haven't been there for about 15 years but they helped me sort out my CD175 I had on my Sigma Turbo with tuning issues.

I'd say that normal carby shops that don't specialise in constant velocity carbies are going to do you more harm than good. That was my Dad's experience with his Rover P6B after going to Ultratune back in the day.

Home (http://www.sumidel.com)

[Homestar]

Adjustment and tuning isn’t hard either, not sure why so many get scared of them, but if they were working fine before as you said, a good clean and blow,out should sort them, they are heaps simpler than other carbies. The rubber diaphragms in the top can perish which will stop them pretty quick, but that’s a 5 minute fix. 👍

[Bigbjorn]

G'day Garry,

I would't go anywhere else than Sumidel in Lakemba in Sydney. They are SU specialists and really know what they are doing. I haven't been there for about 15 years but they helped me sort out my CD175 I had on my Sigma Turbo with tuning issues.

I'd say that normal carby shops that don't specialise in constant velocity carbies are going to do you more harm than good. That was my Dad's experience with his Rover P6B after going to Ultratune back in the day.

Home (http://www.sumidel.com)

SU-Midel! See your bank manager first.

[101RRS]

Well part of the problem is that the mud wasps built a nest in the rubber fuel hose half way between the filter and where the hose would have joined the left carb - fuel pressure pushed it to the first carb where it blocked the inlet sending the fuel back to the tank.

Gotta buy some cheap 13mm spanners tomorrow to modify so that I can undo the carbs from the manifold - isn't it amazing how the nuts in the easiest spots come off the easiest but the nuts in the tightest spot underneath everything else are the hardest to get out.

Once the carbs are off I will do a basic internal clean and hopefully not too much mud wasp mud went in.

[PhilipA]

As I guess you know, all you have to do to the spanner is to bend the head about 20degrees.
Aren't they 1/2 or 9/16 AF?
I think I still have mine from 20 years ago.
Regards Philip A

[101RRS]

As I guess you know, all you have to do to the spanner is to bend the head about 20degrees.
Aren't they 1/2 or 9/16 AF?
I think I still have mine from 20 years ago.
Regards Philip A

You are probably correct - but 13mm fits spot on. It is 11 years since I had had the carbs off the manifold and I cannot remember what I did then.

Cheers

Garry

[101RRS]

Ok carbs are off but not dissembled at this stage - looks like the mud wasps are the culprits.

So for those who may have to remove the carbs form their 3.5 in the future - it can be done without removing linkages (except the one that joins the carbs) so adjustments do not change. The nuts are 1/2" which is exactly the same as 13mm so both are interchangable (as is 14mm and 9/16th).

Now normal ring/open end spanners will not fit and you will have to modify some. Usual crap Brit poor design but is doable.

So you will need to go to either SuperCheap or to Bunnings and go to their cheap spanner buckets - I went to Bunnings and bought 3 13mm and 3 1/2" spanners for $1.50 each - they are cheap for a reason.

So here is what I then made.

https://live.staticflickr.com/65535/40725398823_9fa8c9aba2_b.jpg (https://flic.kr/p/253LjdF)IMG_20190424_162944 (https://flic.kr/p/253LjdF)

The top spanner is a standard 13mm spanner - you can do a couple of the nuts with it.

Next is a slightly shortened spanner - needed for the front left nuts where the top radiator hose is in the way - note the ground open ends to make the teeth thinner to get in tight.

The next is a stumpy needed for the very bottom bolts - needs to be short enough to swing under the carbs and not touch the engine - if the nut is tight then the shortened spanner can levered undone.

The last spanner is modified so it can get to the bottom nuts from underneath the carbs - depending on the position of the nuts it can be easier to use this spanner rather than the stumpy.

A strong magnetic pickup is helpful to not loose the nuts and spring washers.

Hope this helps - I last did this job 11 years ago and all I can remember is that it was a pain to do which it is somewhat.

Garry

[101RRS]

Yep mud wasps - they must have been small as the initial nest was about 5cm deep inside the rubber fuel line not at the end as they usually are - rubber and the smell of oil/petrol normally puts them off.

So when the fuel pump activated it pushed part of the nest into the chamber just above the float valve of the first carb where it blocked the valve so all fuel with the rest of the mud nest went to the other carb and blocked the other float valve - so not allowing fuel into both carbs.

The muck stayed at the top of both float valves as an almost solid block and did not go through the valve - just blocked them. Bottom end was relatively clean with just a little fine red dust in the bowl.

So going back together and we will see - experience has shown that if all goes well, you have done something wrong and you will have to do things over.

Garry

[101RRS]

Using my magic tools the carbs only took about 30mins to get back on - and they fired up first go and settled down to a nice idle - the first time it has run on petrol in over 2 years. I cannot wait to get it injected though - will save a lot of heartache trying to start on carbs on ice cold mornings.

So mud wasps - I had sealed most pipes but not the rubber fuel pipe and that is what brought me unstuck.

Cheers

Garry